Second-storey additions, rear additions, coach houses, and legal basement suites. More space, multi-generational living, or long-term rental income, built onto the home you already own. In-house Red Seal trades, engineering coordination, and permits handled end to end.
Quick Answer
Additions and legal suites in Chilliwack run $100K to $150K for a basement suite conversion, $150K to $300K for a rear addition, and $300K to $500K+ for a second-storey addition or coach house. Engineering, permits, and in-house Red Seal trades handled end to end. Bill 44 (SSMUH) now permits up to four units on qualifying lots inside the Urban Growth Boundary.
Why additions are different
The technical difficulty of an addition is not the addition itself. Framers can frame a new second storey. Our plumbers can extend the supply and drain runs. Our electricians can add a sub-panel. What is different is the integration: how the new work connects to the old home without leaks, cold bridges, settling, or warranty issues in year five.
Second-storey additions put you into structural engineering territory. The existing foundation and framing need to carry the new load. Roofs come off and homes get tarped for weeks. Mechanical runs need to be extended up. All of it needs to happen without damaging the finishes below and without water finding its way in during a wet Chilliwack spring.
Coach houses and garden suites are cleaner in some ways (a new detached building) and harder in others (servicing trenches, zoning compliance, Development Permit approval, septic capacity). We run the full path for both.
Because our framers, Red Seal electricians, and Red Seal plumbers are Huntley employees, the integration work gets coordinated in person on site. One project manager runs the whole path: structural, envelope, mechanical, finish. One accountable company, one 12-month workmanship commitment.
The Chilliwack additions context
Not every addition type fits every lot. Bill 44 SSMUH opened more options inside the Urban Growth Boundary. Flood construction levels, ALR rules, and heritage overlays shape what is possible on specific properties. We check the legal frame before we check the physical one.
Where it applies
Tight lot sizes and careful setback math. Rear additions and second-storey additions both need Real Property Report verification before scope locks. Coach houses are often feasible here thanks to Bill 44 SSMUH, which permits up to four units on qualifying lots inside the Urban Growth Boundary.
Where it applies
Hillside and view homes. Additions here often get oriented around the view, with primary-suite expansions pointing west or south. Slope-aware foundation engineering and drainage are planning considerations from day one. Structural reinforcement for multi-level additions is common.
Where it applies
Flood construction level rules block new secondary suites below FCL. In these areas, the addition path is usually above-grade: a coach house, a main-floor suite addition, or an above-garage suite rather than a basement suite. ALR rules also apply in parts of Greendale and Yarrow.
Where it applies
Heritage-registered properties in the Mountain View Heritage Conservation Area require a Heritage Alteration Permit for additions. Rural acreage properties need septic capacity review before adding bedrooms or a secondary dwelling. ALR restrictions apply on many rural parcels.
Recent work
Additions and suites are often the most personal projects on our schedule. A few recent ones with more photography from our current shoot coming soon.
What's in scope
Up, out, down, or detached. We run every permit path and every trade for all of them.
Adding a full or partial second floor on top of your existing home. Structural capacity assessment first, engineering coordination, roof removal, framing the new level, mechanical extensions, and full finish. Done without losing your lot footprint.
Extending the main floor out the back of the home. Family rooms, master suites, kitchen expansions, sunrooms. Foundation work, framing, envelope, mechanical extensions, and finish. Often easier than going up because the roof stays put.
Detached secondary dwellings in the backyard. Permitted through Chilliwack’s Development Permit Area 8 design guidelines. Can function as rental income, in-law housing, home office, or studio. We handle the permit path, the servicing, and the build.
Converting unfinished or partially finished basement space into a legal secondary suite. Separate entrance, code-compliant egress, fire separation, sub-panel, full kitchen, full bathroom. Permit coordination and inspections through occupancy.
Adding a self-contained suite above an existing or new garage. Requires structural reinforcement of the garage below, exterior stair access or integrated entry, full mechanical run, and usually an ALC or zoning review depending on the lot.
Any addition or legal suite requires structural engineering, trade permits, and building permits. We coordinate engineers we have worked with, pull our own electrical and plumbing trade permits directly, and take the building permit path end-to-end so you are not chasing the city.
How a Huntley addition gets built
We walk the home, look at structural capacity (can it take a second storey?), measure setbacks, check septic or sewer capacity, and review zoning against what you are trying to build. Some additions are simple. Some require engineering or ALC review. We tell you honestly which category yours is in.
Architectural or designer drawings, structural engineering for load paths and foundations, mechanical upgrade plans, septic or sewer review if applicable. All finish selections and fixture specifications locked before permit submission.
Building permit, trade permits, Development Permits for coach houses and garden suites, Heritage Alteration Permits where applicable. Materials and fixtures ordered early against the build schedule. Chilliwack permit processing currently runs around 10 weeks.
Foundation, framing, roof, envelope, mechanical rough-in, insulation, drywall, finish. For second-storey additions, we tarp and protect the existing home while the roof is off. For coach houses and garden suites, servicing trenches and foundation go in first.
Final inspections, mechanical commissioning, deficiency walk-through, handover of manuals and warranty documents. The 12-month Huntley Workmanship Commitment begins from handover and covers every trade that worked on the project.
Honest numbers
Most contractors will not publish real numbers on additions because the scope varies so much. We will. These are typical Chilliwack project bands. Final quote is line-itemed after the site visit.
Basement suite conversion
$100K – $150K
Converting existing basement space into a legal secondary suite. Egress windows, fire separation, sub-panel, full kitchen and bathroom, separate entrance. No foundation work, no envelope work.
Rear addition
$150K – $300K
Extending the main floor out the back. Foundation, framing, envelope, mechanical extensions, interior finish. Scope depends on size and whether the addition adds a bathroom or kitchen.
Second-storey / coach house
$300K – $500K
Adding a full floor above an existing home, or building a detached coach house or garden suite from scratch. Engineering, structural reinforcement, full envelope, mechanical, finish.
Premium / complex
$500K+
Large second-storey additions with premium finishes, coach houses with multiple bedrooms and high-end materials, or combining additions with whole-home renovation scope.
Typical Chilliwack and Fraser Valley ranges, not quotes. Actual pricing depends on scope, engineering, servicing, and finish level. Final quote is line-itemed after site visit.
Additions & Suites
The questions every homeowner asks when they are weighing an addition, a coach house, or a legal suite. The honest answers.
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Send a message →How we compare
Additions are renovations plus a new building stuck to your existing one. Integration is where most projects fail. Here is how Huntley structures the work differently.
Typical Chilliwack contractor
Huntley Construction
Engineering coordination
Typical
Owner manages structural engineer separately from contractor
Huntley
We coordinate engineering and structural sign-offs directly
Permit path
Typical
Building, trade, Development Permit each handled by different parties
Huntley
All permits run through Huntley end to end
Envelope integration
Typical
New addition leaks at the seam where it meets the existing home
Huntley
In-house team coordinating envelope, flashing, and water management
Mechanical extensions
Typical
Sub-trade scheduling delays as electrical/plumbing extend up or out
Huntley
In-house Red Seal trades handle extensions on the same schedule
Coach house servicing
Typical
Owner coordinates trenching with city, water, sewer, electrical separately
Huntley
Servicing trench planned and coordinated as part of the build
Workmanship warranty
Typical
Sub-trade dependent
Huntley
12-month commitment covering every trade that worked on the addition
Related work
Keep researching
Plain-English guide to legal suite zoning, egress, and permits.
Read postWhich option fits your lot, and which earns more long term.
Read postUp to four units on most single-family lots. What the rules allow.
Read postWhen you need a permit, what they cost, and how long they take.
Read postReady to plan
We come to your property, look at the structural feasibility and the zoning, and talk honestly about what is possible. Second-storey, rear addition, coach house, or legal suite. Site visit, clear scope, line-item quote.